Researchers to explore links between breast cancer and breastfeeding

Researchers at Imperial College London have been awarded £150,000 in funding to investigate how breastfeeding lowers the risk of breast cancer.

The award will enable Dr James Flanagan and PhD student Sophia D’Alessandro to study whether the length of time a woman breastfeeds affects her breast cancer risk.

Breastfeeding has been linked to a lower risk of developing breast cancer, with previous data analysis showing the risk of developing the disease decreases by four per cent for every 12 months of breastfeeding. But it’s not yet clear why.

It is possible that breastfeeding alters the balance of hormones in the body, or protects breast cells in some way, making them less vulnerable to changes that cause cancer.

In previous research, Dr Flanagan and his team found that breast milk sometimes contained cells with potentially cancer-causing changes in their DNA, but they only found these cells in the milk of women who had breastfed for less than four months.

Now, in this new project, they want to find out if breastfeeding for longer periods of time removes these cells and whether factors, such as weight, exercise, or smoking, are linked to the presence of the cells.

Using breast milk samples donated by 300 women taking part in the Breastmilk Epigenetics Cohort Study (BECS), coordinated in partnership with the Human Milk Foundation, the researchers will screen for these cells. They will collect samples every few months from the same women to see if changes that were initially detected are reduced in later samples.

“We believe that preventing breast cancer is the best way to reduce the number of deaths from the disease, so we need to understand what things women could do to reduce their risk,” Dr Flanagan explained.

“We hope to use the knowledge from this study to prevent as many breast cancers as possible.”

Working with professor Amy Brown at Swansea University, the team will also interview some of the women in the study to find out whether they would want to be made aware of the detection of DNA changes in their breast milk and how they might feel about public health messaging that conveys they could be at greater risk.

With only 48 per cent of women continuing to breastfeed beyond six to eight weeks in the UK, the researchers are keen to understand whether women might decide to breastfeed for longer if they could find out that they were potentially at risk of breast cancer.

Dr Simon Vincent, Breast Cancer Now’s director of research, support and influencing, said: “With 55,000 women diagnosed with breast cancer every year in the UK, and this number expected to rise to 69,000 diagnoses a year by 2030, we need to fully understand how breastfeeding can influence this risk.

“While we are very aware that breastfeeding isn’t an option for all women and that this is a sensitive topic, we are delighted to fund more research in this area as it will help us continue to improve the information and advice that we provide to women on breast cancer risk.”

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